Pre-heat the oven to 425F.,In a large bowl, mix together the pumpkin, yogurt, flour, sweetened condensed milk, egg yolks, and vanilla extract.,Stir in cloves ,nutmeg ,ginger,cinnamon and salt.,In a mixing bowl, whip egg whites until soft peaks form.,Gently fold into pumpkin mixture.,______,Bake for 15 minutes in the pre-heated oven.,While the pie is baking, prepare the cinnamon topping.,In a small bowl, combine the flour, turbinado sugar, and cinnamon.,Blend in the cold butter with a fork or pastry blender until the mixture is crumbly.,Mix in the chopped roasted nuts, remove the pie from the oven and sprinkle the topping over the pie.,Return to oven and reduced the heat to 325 F. Bake an additional 45 minutes, or until set.,Remove and cool completely and refrigerate 2 hours before cutting.,Top with whipped cream or whipped topping when serve if desired.